How did John von Neumann solved the fly and bicycles puzzle?
This famous puzzle goes like this: Two bicycles are traveling toward each other at the same speed until they collide; Meanwhile a fly is traveling back and forth between them, also at a constant speed. The bicycles start 20 miles apart, and travel at 10 miles per hour, and the fly travels at 15 miles per hour. How far does the fly travel in total? If you don’t know this puzzle I suggest that you stop and think a bit about it, see if you can solve it....